1. Special Focus: Carbon Nanostructures

2. Carbon Nanostructures
Buckyballs
Nanotubes
SWNT & MWNT
(single-walled nanotubes & multi-walled nanotubes)
Graphene thin layers

3. Carbon Nanostructures
Metallic conductor (graphite)
Variety of properties
Insulating Polymer (hydrocarbon chains)
Semiconductor (diamond)
3-D
Variety of structures
2-D
1-D
0-D

4. Carbon Fullerenes 0-dimensional carbon structure
Usually C60, but also refers to C70, C76, Cn (n > 60)
Every carbon site on C60 is equivalent
Bonded to three other carbons
average bond is 1.44 Å (C-C is 1.46 Å; C=C is 1.40 Å)
20 hexagonal faces; 12 pentagonal faces
Diameter: Å (7.1 x m)

5. Buckminster Fuller (1895-1983):
Architect, engineer, inventor; Developed the geodesic dome

6. Epcot Center in Disneyworld

7. Climatron at the Missouri Botanical Garden

8. Biosphere Museum in Canada

9. The shape of the geodesic dome encloses the greatest volume while taking up the least surface area.
Fuller hoped the design would produce large numbers of inexpensive homes for soldiers returning from WWII.
The building can withstand high winds such as those found in hurricanes.

10. Synthesis of Fullerenes
Laser ablation (vaporizing graphite with a laser)
Plasma arcing of graphite or coal
Fullerenes found in the soot e- C+
Anode
Cathode
Nanotube deposit
Combustion synthesis
Burn hydrocarbon at low pressure

11. Demo: Laser Pointer, watch plate, Charcoal briquette!

12. Single-Walled Carbon Nanotubes (SWCNT; SWNT)
Multi-Walled Carbon Nanotubes (MWCNT; MWNT)
How to make them:
Arc evaporation (plasma arcing)
Laser ablation
PECVD (plasma-enhanced chemical vapor deposition)
Electrochemical methods

13. Carbon Nanotubes
Armchair
(b) Zigzag
(c) Chiral

14. Properties of Carbon Nanotubes
Mechanical
Stiff and robust structures
C-C bonds in graphite (and nanotubes) is the one of the strongest bonds in nature
Flexible; do not break when bent
Conductivity
Extremely high thermal conductivity
Extremely high electrical conductivity
Potential Applications:
catalysis - hydrogen storage - biological cell electrodes
resistors - flow sensors - electron field emission tips
electronic/mechanical devices - scanning probe tips

16. Carbon Nanotube Applications: NEMS: Nanoelectricalmechanical systems
“Nantero is a nanotechnology company using carbon nanotubes for the development of next-generation semiconductor devices...
In the field of memory, Nantero is developing NRAM™, a high-density nonvolatile Random Access Memory.”
Gold plate ~ (100 nm)2 attached to outer shell of suspended MWCNT (on Si wafer)
“electrostatically rotate the outer shell relative to the inner core”

17. WATCH CLIP FROM “NOVA: Making Things Stronger” about Carbon Nanotubes (Scene Selection)